Side impact events in vehicles have been identified as one of the top priorities for both research and regulation with government requirements continuing to become more stringent. As a result of the multiple test dummy sizes, the pelvic bolster stiffness target must be well maintained in all side impact scenarios. Particularly, in a side impact event, the pelvic bolster may deform prior to occupant contact (so-called “pre-crush”) as the bolster is constrained between the door trim panel and the intruding door sheetmetal. Data illustrate that the amount of deformation of the pelvic bolster varies with different test modes and occupant sizes. These variations alter the targeted pelvic bolster stiffness and have great effect on occupant performance as seen in many tests. Since the pelvic bolster stiffness is typically optimized as contact stiffness with the test dummies, protection of the pelvic bolster from pre-crush becomes critical for occupant performance in side impact.
Accordingly, as in so many areas of vehicle technology, there is room in the art of vehicle door design for an alternative configuration to known pelvic bolster structures which provides effective protection that can be adapted to a variety of shapes while maintaining relatively low manufacturing and assembly costs.